Some bandwidth compression systems for speech transmission

The nature of speech is discussed, and the channel capacity required for transmitting speech signals by conventional means is considered. A review is given of methods which have been suggested by various workers for processing the speech signals so that they may be transmitted over channels of lower capacity. A description is given of a simple `formant tracker¿ for speech analysis, using a system of successive binary comparisons. Tests which have been carried out with the apparatus are described, including its use with a simple speech synthesizer to demonstrate the principle of analysis-synthesis telephony.